Look at these: `1 xx 4=(2 xx 3)=2` `2 xx 5=(3 xx 4)-2` `3 xx 6=(4 xx 5)-2` `4 xx 7=(5 xx 6)-2` i) Write the next two lines in this pattern. ii) If we take four-consecutive natural numbers, what is the relation betweén the prodụcts of the first and the last, and the product of the middle two? iii) Write this as a geheral "principle in .álgebra and explain it.

Explanation

i) `5 xx 8=(6 xx 7)-2`
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6 xx 9=(7 xx 8)-2
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ii) The product of the first and last is two less than the product of the middle țwo."
iii) Four consecutive numbers be `l`
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x, x+1, x+2, x+3
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